1. Field of the Invention
The present invention relates to a vehicle steering system, and more particularly, to a vehicle steering system including an irrotational airbag module in which an airbag module is mounted independently of the rotation of a steering wheel.
2. Description of Related Art
In general, safety devices for a vehicle are classified into active safety devices (brake, antilock brake systems or ABS, traction control systems or TCS, and navigation systems) that prevent an accident from occurring, and passive safety devices (safety belts, airbags, and pretensioners) that protect a passenger when an accident occurs.
Among such safety devices, an airbag system is a device that inflates an airbag before a secondary collision of a passenger in order to protect a passenger during a collision. Airbag systems are generally provided adjacent a driver seat and/or a passenger seat in order to prevent a face of a driver and/or a passenger from being injured.
Among the airbag systems, an airbag module of a driver's seat is generally mounted on a hub of a steering wheel. Therefore, when a steering wheel is rotated, the airbag module is also rotated.
Since the airbag module is rotated together with the steering wheel as described above, a particular connecting member, a so called SRC clock spring that is used to connect a wire harness to a rotating part (e.g., steering wheel) is used in order to prevent power cables or signal lines, which are connected to an inflator, from interfering due to the rotation
However, the airbag of a driver's seat, which is mounted on the steering wheel and generally rotates together with the steering wheel during steering, has various limitations. For example, an airbag cushion, which is deployed during the operation of the airbag, should be deployed so as to sufficiently protect a driver regardless of the position of the steering wheel. For this reason, the airbag cushion should always have a symmetrical shape, and the airbag of the driver's seat cannot have an asymmetrical optimum shape unlike the airbag of the passenger seat. Further, the lower portion of the deployed cushion strongly presses the chest of the passenger, so that the passenger may be injured.
In addition, since the logo formed on the airbag module of the driver's seat is rotated together with the steering wheel, the design visibility of the logo deteriorates. Further, a sensor, which is provided on a crash pad so as to detect that a driver dozes off at the wheel, may be covered depending on the rotation of the steering wheel. As a result, the performance of the sensor deteriorates.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.